Peelable couponable labels are well known in the art. Typically such labels employ a dry adhesive such as is described by Dunsirn et al. in U.S. Pat. No. 4,479,838 wherein a “dry residue” adhesive without a release layer is used which results in a tack free bond. However, the dry adhesive of these labels splits leaving adhesive on both label surfaces. Moreover, when a paper label substrate is used in the dry bond approach of the prior art, typically the bond of the dry bond adhesive becomes greater on aging than the strength of the paper fibers resulting in fiber tear on attempting to peel the label or coupon. This results unavoidably in the tearing of one or both of the paper labels if it is an all-paper construction or the transfer of indicia on the paper fiber from one surface to the other which removes required indicia from one face and adheres it unwanted to the other label face. In cases where the substrate is a polymer the problem of increase in bond strength with aging reduces the peelability of the label.
The release layer of the present invention solves the problems associated with the dry bond adhesive approach by utilizing a conventional release layer and pressure sensitive “tacky” adhesive which can be produced on conventional laminating equipment.
The present invention also solves the manufacturing problems associated with the prior art. Namely, costly special machinery is required to laminate two preprinted webs of paper or polymer in register to produce the types of couponable structures of the prior art. In the present invention, by printing label graphics in reverse (random or registered) on the back side of the face label directly on the release layer, the graphics will be transferred to the adhesive on the face of the base label. All of the graphics can be printed on the primary face web in one press pass using the front and back side of the primary web. The graphics printed in reverse on the release layer will adhere and transfer to the tacky adhesive when laminated. By using this technique with registered indica, any conventional adhesive laminator can use tacky adhesive to produce registered couponable labels without special equipment to register two printed webs of paper or polymer. In addition, since the ink is transferring to the surface of the tacky adhesive, there will not be tack in the inked areas since the tacky adhesive is masked by the ink.